The present invention relates to a data processing method for hybrid automatic repeat for request (hereinafter, referred to as an ARQ) type II/III on a downlink of a wide-band radio communication system; and, more particularly, to a method for processing a radio link control protocol data unit (RLC-PDU) and a HARQ-RLC-Control-PDU, which is extracted from the RLC-PDU, by using a transport channel such as a downlink shared channel (DSCH), wherein the RLC-PDU is used in W-CDMA based on a next generation mobile communication network, such as an international mobile telecommunication (IMT)-2000 and a universal mobile telecommunications system (UMTS), and to a recording media having a computer readable program for carrying out the method.
Terms used in this specification will be described.
xe2x80x9cA radio network controller-radio link control (RNC-RLC)xe2x80x9d is a radio link control protocol level entity of a radio network controller (RNC).
xe2x80x9cA radio network controller-medium access control dedicated entity (RNC-MAC-D)xe2x80x9d is a medium access control protocol level dedicated entity of a radio network controller (RNC).
xe2x80x9cA radio network controller-medium access control common/shared entity (RNC-MAC-C/SH)xe2x80x9d is a medium access control protocol level terminal common/shared entity of a radio network controller (RNC).
xe2x80x9cNode B-L1xe2x80x9d is a physical channel layer entity of a node B. The node B represents a base transceiver station (BTS) in an asynchronous IMT-2000 system. In this specification, the node B is used as the same meaning as the base transceiver station (BTS).
xe2x80x9cUser equipment-L1 (UE-L1)xe2x80x9d is a physical channel level entity of a user equipment (UE) (or a mobile station).
xe2x80x9cUser equipment-medium access control common/shared dedicated entity (UE-MAC-C/SH)xe2x80x9d is a medium access control protocol level terminal common/shared entity of a user equipment (UE) (or a mobile station).
xe2x80x9cUser equipment-medium access control dedicated entity (UE-MAC-D)xe2x80x9d is a medium access control protocol level terminal dedicated entity of a user equipment (UE) (or a mobile station).
xe2x80x9cUser equipment-radio link control (UE-RLC)xe2x80x9d is a radio link control protocol level entity of a user equipment (UE) (or a mobile station).
xe2x80x9cUser equipment-radio resource control (UE-RRC)xe2x80x9d is a radio resource control protocol level entity of a user equipment (UE) (or a mobile station).
xe2x80x9cIubxe2x80x9d denotes an interface between the RNC and the Node B (BTS).
xe2x80x9cIurxe2x80x9d denotes an interface between the RNC and another RNC.
xe2x80x9cUuxe2x80x9d denotes an interface between the Node B and the UE.
xe2x80x9cLogical channelxe2x80x9d is a logical channel used for transmitting and receiving data between the RLC protocol entity and MAC protocol entity.
xe2x80x9cTransport channelxe2x80x9d is a logical channel used for transmitting and receiving data between the MAC protocol entity and a physical layer.
xe2x80x9cPhysical channelxe2x80x9d is a practical channel used for transmitting and receiving data between a mobile station and a BTS.
When transporting the data from a radio network of a UMTS terrestrial radio access network (UTRAN) to the mobile station (MS), a Hybrid ARQ type II/III which has superior throughput than a Hybrid ARQ type I may be used.
FIG. 2 is a diagram showing a general wide-band radio communication network (WCDMA). A UTRAN environment is used as an example in this drawing.
As described in FIG. 2, the UTRAN includes a user equipment (UE) 10, an asynchronous radio network 20 and a radio communication core network 30, such as a GSM-MAP core network.
A Hybrid ARQ type II/III is adapted between the UE and the asynchronous radio network 200. When a received data has an error, a receiving part requests a transmission part to re-transmit the received data.
A protocol stack structure in the above-referenced interlocking structure is illustrated in FIG. 4.
FIG. 3 is a diagram showing a general UTRAN. In FIG. 3, the In is an interface between the radio communication core network 300 and the asynchronous radio network 200, and, the Iur means a logical interface between radio network controllers (RNC) of the asynchronous radio networks 200 and the lub shows an interface between the RNC and the Node B. Meanwhile, the Uu shows a radio interface between the UTRAN and the UE.
In here, the Node B is a logical node, which is responsible for a radio transmission/receiving from one or more cell to the UE.
Generally in the UTRAN, if a received data has an error, the receiving part requests re-transmission of the data to the transmission part by using an automatic repeat request (ARQ) method. The ARQ method is divided to ARQ type I, II and III, and technical characteristics of each type are described below.
The ARQ is an error control protocol, which automatically senses an error during transmission and then requests re-transmission of the error-containing block. That is, the ARQ is one of data transmission error control methods, and when an error is detected, automatically generates a re-transmission request signal to cause re-transmission of the data.
The ARQ method is used in the UTRAN for a transmission packet data. The receiving part requests the transmission part to re-transmit an error-containing packet. However, when using the ARQ method, if the number of re-transmission requests are increased, then the throughput, which is amount of data transmitted in a predetermined period, is decreased. To solve the problem, the ARQ can be used along with a forward error correction coding (FEC) method, which is called as a hybrid ARQ.
The hybrid ARQ has three types I, II and III.
In case of type I, one coding rate is selected, for example, one coding rate selected from no coding, rate 1/2 and rate 1/3 of convolutional codings, according to channel environment or required quality of service (QoS) and the selected coding rate is continuously used. If there is a re-transmit request, the receiving part removes pre-received data and the transmission part re-transmits the data with the pre-transmitted coding rate. In this case, the coding rate is not changed according to changeable channel environment, so, when compared with the type II and III the throughput may be decreased.
In case of type II ARQ, if the receiving part requests data re-transmission, then the data is stored onto a buffer at the receiver and the stored data is combined with the retransmitted data. That is, at first, the data is transmitted with a high coding rate and in case of re-transmitting, the data is transmitted with a lower coding rate and it is combined with the pre-received stored data to increase efficiency compared to the type I. For example, a convolutional coding rate 1/4, which is a mother code, may generates coding rates 8/9, 2/3 or 1/4 by puncturing, and it is called a rate compatible punctured convolutional (RCPC) code. The RCPC code is illustrated in FIG. 1.
Meanwhile, a rate compatible punctured turbo (RCPT) code is obtained by puncturing a turbo code. Referring to FIG. 1, at first, a data is transmitted with a coding rate of 8/9, and this version of the data is called as ver(0), an error is detected in the data by checking a cyclic redundancy check (CRC) and the data is stored to a buffer and re-transmission is requested. At this time, the re-transmission is performed with a coding rate 2/3 and the re-transmission version is designated ver(1).
The receiving part combines the ver(0) data stored in the buffer and the ver(1) data, then the combined data is decoded and checked by the CRC. The above-referenced process is repeated until no error is detected, then, the last transmitted ver(n) is combined with a pre-transmitted ver(nxe2x88x92a)(0 less than a less than n).
The type III ARQ is similar to the type II ARQ. It is different in that the re-transmitted ver(n) data is decoded before combined with the ver(nxe2x88x92a) data, and checked by the CRC then, if there is no error, the ver(n) data is transmitted to an upper layer. If an error is detected, the retransmitted ver(n) data is combined with ver(nxe2x88x92a) and checked by the CRC to determine if further data re-transmission is necessary.
Accordingly, the hybrid ARQ type II/III is used for efficient data transmission in the UTRAN.
The hybrid ARQ type II/III combines a first data which is encoded with a high coding rate and a re-transmit data which is encoded with a low coding rate in the receiver to increase the throughput. Therefore, relational information between a sequence number and a retransmitted version of a protocol data unit (PDU) is needed to be known in advance. The relation information should be transmitted with a low coding rate, regardless of the retransmission coding rate, thereby ensuring its quality of communication.
However, for the hybrid ARQ type II/III in the UTRAN, the data is transmitted with the high coding rate, thereby increasing the possibility of an error of a header of a RLC-PDU. Therefore, a method of stably transmitting the RLC-PDU header is required.
It is, therefore, an object of the present invention to provide a data delivery method for hybrid ARQ type II/III on the downlink of wide-band radio communication system and a computer readable recording media for having instructions for performing the method.
In accordance with an aspect of the present invention, there is provided a data processing method for a hybrid ARQ type II/III on a downlink of a wide-band radio communication system, wherein a serving radio network controller (hereinafter, referred to as a SRNC) which is directly connected to a user equipment to allocate wireless resources to the user equipment and provides services by interlocking with a wireless communication core network in case of a call connection and a controlling radio network controller (hereinafter, referred to as a CRNC) which controls a sharing channel of a radio network are located on the same radio network, comprising the steps of: a) generating a radio link control-protocol data unit (hereinafter, referred to as a RLC-PDU) in a radio link control (hereinafter, referred to as a RLC) layer of the SRNC, and generating a part having RLC-PDU information needed for supporting the hybrid ARQ type II/III based on a header of the RLC-PDU (hereinafter, referred to as a HARQ-RLC-Control-PDU); b) transmitting the RLC-PDU and the HARQ-RLC-Control-PDU to a medium access control dedicated (hereinafter, referred to as a MAC-D) treating a general user part of a MAC layer through a logical channel; c) transmitting the RLC-PDU and the HARQ-RLC-Control-PDU from the MAC-D to a medium access control common/shared (hereinafter, referred to as a MAC-C/SH) treating common/shared channel part of the MAC layer; d) transforming the PLC-PDU and the HARQ-RLC-Control-PDU to MAC-PDU and the HARQ-MAC-Control-PDU, respectively, in the MAC-C/SH and allocating a transport format indicator 1 (TFI1) of the MAC-PDU and a transport format indicator 2 (TFI2) of the HARQ-MAC-Control-PDU and transmitting the TFI1 and TFI2 to the MAC-D, and transmitting the MAC-PDU and the HARQ-MAC-Control-PDU to a physical layer of BTS, through a transport channel; and e) forming the TFI1 and the TFI2 of the MAC-D to a transport format combination set (TFCI) then transmitting the TFCI to the user equipment through a first physical channel, and transforming the MAC-PDU and the HARQ-MAC-Control-PDU to a radio frame, then transmitting the radio frame to the mobile station through a second physical channel.
Also, the present invention may further comprising the step of: f) storing the RLC-PDU to a buffer, extracting the RLC-PDU of the buffer by using the HARQ-RLC-Control-PDU, transmitting the RLC-PDU to an upper layer after interpreting and transmitting the response to the radio network.
In accordance with another aspect of the present invention, there is provided a computer readable data recording media embodying instructions for the hybrid ARQ type II/III on a downlink of a wide-band radio communication system, wherein a serving radio network controller (hereinafter, referred to as a SRNC) which is directly connected to a user equipment to allocate wireless resources to the user equipment and provides services by interlocking with a wireless communication core network in case of a call connection and a controlling radio network controller (hereinafter, referred to as a CRNC) which controls a sharing channel of a radio network are located on the same radio network, comprising the functions of: a) generating a radio link control-protocol data unit (hereinafter, referred to as a RLC-PDU) in a radio link control (hereinafter, referred to as a RLC) layer of the SRNC and generating a part having RLC-PDU information needed for supporting the hybrid ARQ type II/III based on a header of the RLC-PDU (hereinafter, referred to as a HARQ-RLC-Control-PDU); b) transmitting the RLC-PDU and the HARQ-RLC-Control-PDU to a medium access control dedicated (hereinafter, referred to as a MAC-D) treating a general user part of a MAC layer through a logical channel; c) transmitting the RLC-PDU and the HARQ-RLC-Control-PDU of the MAC-D to a medium access control common/shared (hereinafter, referred to as a MAC-C/SH) treating common/shared channel part of the MAC layer; d) transforming the PLC-PDU and the HARQ-RLC-Control-PDU to MAC-PDU and the HARQ-MAC-Control-PDU, respectively, in the MAC-C/SH and allocating a transport format indicator 1 (TFI1) of the MAC-PDU and a transport format indicator 2 (TFI2) of the HARQ-MAC-Control-PDU and transmitting the TFI1 and TFI2 to the MAC-D, and transmitting the MAC-PDU and the HARQ-MAC-Control-PDU to a physical layer of BTS, through a transport channel; and e) forming the TFI1 and the TFI2 of the MAC-D to a transport format combination set (TFCI) then transmitting the TFCI to the user equipment through a first physical channel, and transforming the MAC-PDU and the HARQ-MAC-Control-PDU to a radio frame, then transmitting the radio frame to the mobile station through a second physical channel.
Also, the present invention further comprising the step of: f) storing the RLC-PDU to a buffer, extracting the RLC-PDU of the buffer by using the HARQ-RLC-Control-PDU, transmitting the RLC-PDU to an upper layer after interpreting and transmitting the response to the radio network.
The present invention is a method for realizing the hybrid ARQ type II/III on the downlink of an asynchronous mobile communication system which includes the CRNC and the SRNC, and may be adapted in a technical field where packet data service is used.
In an asynchronous communication system which has the CRNC and the SRNC on a same asynchronous network, the present invention of using the hybrid ARQ type II/III may increase system efficiency by combining a changeable coding rate, a pre-transmitted data and a re-transmitted data.
To perform the combining on the hybrid ARQ type II/III, the receiving part may know information of the current receiving RLC-PDU, and the information composing part of the RLC-PDU should be transmitted more stably than transmitted data.
For the above, the present invention generates the HARQ-RLC-Control-PDU referring to the RLC-PDU, wherein the HARQ-RLC-Control-PUD has information of the RLC-PDU which is used for supporting the hybrid ARQ type II/III. At this time, the HARQ-RLC-Control-PDU includes sequence number of the RLC-PDU and a version number.
The RLC-PDU and the HARQ-RLC-Control-PUD are transmitted from a RLC protocol entity to a MAC-D protocol entity by using a different or same logical channel and transmitted from a MAC-C/SH protocol entity to a physical layer by using a downlink shared channel (DSCH) and transmitted to a receiving part through a physical channel, such as a physical downlink shared channel (PDSCH).